The invention relates to fuzes for high explosives, particularly to fuzes for insensitive high explosives, and more particularly to an insensitive fuze train for high explosives.
Over the years various approaches have been made for safely igniting a high explosive charge. When employing explosives for the purpose of excavation, strip mining, and related earth moving activities, it has been a common practice to use blasting caps having electrical initiators, such as exemplified by U.S. Pat. No. 5,052,301 issued Oct. 1, 1991 to Richard E. Walker.
In various types of military ordinance and in a great many applications of high explosives in the civil sector, there has been a continuing effort to develop safe, reliable detonators which can be routinely activated by small amounts of electrical energy, such as exemplified by U.S. Pat. No. 4,316,412 issued Feb. 23, 1982 to Robert H. Dinegar et al. and U.S. Pat. No. 4,907,509 issued Mar. 13, 1990 to Morton L. Lieberman.
Another approach to the need for effective detonators for various types of explosive application was the thin film bridge detonator wherein a primer is placed on a thin film bridge and when sufficient current passes through the bridge its inherent resistance heating will fire or detonate the primer, which in turn will detonate the primary charge. These prior thin film bridge detonators are exemplified by U.S. Pat. No. 4,729,315 issued Mar. 8,1988 to Robert L. Proffit et al.
A different approach to detonation of high explosives is known as the "slapper detonator", as described in a Lawrence Livermore National Laboratory document, UCRL-77639 by John R. Stroud, entitled "A New Kind Of Detonator--The Slapper", dated Feb. 27, 1976, which operates by exploding a thin metal foil that accelerates a plastic film or flyer across a gap to impact on a high-density secondary explosive, which in turn initiates a main charge explosive. More recent detonators utilizing the "slapper" approach are exemplified by U.S. Pat. No. 4,928,595, issued May 29, 1990 to Richard C. Weingart and U.S. Pat. No. 5,080,016 issued Jan. 14, 1992 to John E. Osher.
The U.S. Department of Defense is currently interested in reducing weapon vulnerability and improving weapon safety in extreme and abnormal environments. Insensitive munitions are one way to achieve these goals. High explosive (HE) weapon fills in insensitive munitions have large failure diameters, and they are difficult to initiate intentionally. Thus, a fuze train is needed that will ignite these insensitive munitions at extremes of temperature, but will not compromise the insensitivity of the HE main charge fill to external threats.